Numerical Optimization of Bearing Length in Composite Extrusion Processes

Abstract

The decrease of the bearing length in extrusion processes results in increasing of the material flow and offers, through this, the possibility for manipulation and optimization. This paper presents a simulation based optimization technique which uses this effect for optimizing the material flow in direct extrusion processes. Firstly, the method is used in a multi-extrusion process with equal pitch circle profiles, then in an extrusion process of an asymmetric profile. Furthermore, a composite extrusion process is analyzed where endless wires of high strength steel are embedded in a base material of aluminum. The insertion of reinforcement elements into the base material flow, especially within the small ratio between profile thickness and the reinforcement diameter, can lead to significant local disturbances inside the die, which result in undesirable profile defects. Hence, the simulation-based optimization method is especially used to optimize inhomogeneous wall thicknesses in composite profiles.

Experimental and Numerical Analysis of the Friction Condition in the Die Bearing during Aluminum Extrusion

“…If the modeling of the extrusion is done without considering friction all profiles are exiting the die with almost the same speed and therefore, have the same profile length. But if the model is upgraded with a calculation of the friction, which occurs during the extrusion of aluminum alloys, the FEM simulation shows a large difference in the profiles speed [1,2].…”

Extrusion Benchmark 2013 - Experimental Analysis of Mandrel Deflection, Local Temperature and Pressure in Extrusion Dies

“…It is then clear that software tools supporting die design are essential for an effective and reliable ´one step die design´. Therefore in the past years, it has been demonstrated that finite element simulation (FEM) is a powerful tool for analyzing the relation between the process parameters, the tool design, and the product properties [1,2].…”

Grain size evolution simulation in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process

“…Indeed, several papers are available on the simulation of the extrusion process, and almost all the aspects of the extrusion process have been investigated and modelled. The friction behaviour inside the container was investigated by Bakhshi-Jooybari12 and Schikorra et al 13; the material flow in two or three dimensions by Kalz14 and Valberg,15 a validation of flow stress distribution by means of tools deflection by Donati et al 16 In addition, FEM tools can be used to optimise the material flow, or, as proposed by Kloppenborg et al ,17 an analysis of extrusion of a composite material. All the papers evidenced as FEM simulation are a powerful tool for process analysis and optimisation, but still today, a 10–20% average error rate on process load or material flow is found in particular when Lagrangian codes are used 18.…”